A New Touch for iPhone

Fingerprint Technology, New System Make the 5S the Leader of the Smartphone Pack

By

Walter S. Mossberg

Updated Sept. 18, 2013 12:55 p.m. ET

Apple brings out a new top-of-the-line iPhone model every year, but a redesign only every other year. In the intervening cycles, the company tends to keep the phone's exterior the same, but change the innards and the software. This is one of those in-between years, but the new iPhone 5S has a potentially game-changing hardware feature and a radically new operating system.

The iPhone 5S is the first digital device I've seen with a simple, reliable fingerprint reader—one you can confidently use, without a thought, to...